How to restrict <input type=“file”> so that it can only select .pdf files?

Question

By default it can select all type of files,how to restrict it so that it can only select .pdf files?

Answer 1

Simply put: you can't using the plain html and javascript. The closest you can get is to test the file extension using javascript before submitting the form and show some error message to the user if it is other than .pdf. You might need to use some client side solution such as Flash upload controls if you want to achieve this.